nuttx-apps/graphics/ft80x/ft80x_ramg.c

/****************************************************************************
 * apps/graphics/ft80x/ft80x_ramg.c
 *
 *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sys/ioctl.h>
#include <stdint.h>
#include <assert.h>
#include <errno.h>

#include <nuttx/lcd/ft80x.h>

#include "graphics/ft80x.h"
#include "ft80x.h"

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: ft80x_ramg_write
 *
 * Description:
 *   Write to graphics memory
 *
 * Input Parameters:
 *   fd     - The file descriptor of the FT80x device.  Opened by the caller
 *            with write access.
 *   offset - Offset in graphics memory to write to (dest)
 *   data   - Pointer to a data to be written (src)
 *   nbytes - The number of bytes to write to graphics memory.
 *
 * Returned Value:
 *   Zero (OK) on success.  A negated errno value on failure.
 *
 ****************************************************************************/

int ft80x_ramg_write(int fd, unsigned int offset, FAR const void *data,
                     unsigned int nbytes)
{
  struct ft80x_relmem_s ramg;
  int ret;

  DEBUGASSERT(data != NULL && nbytes > 0 &&
              (offset + nbytes) < FT80X_RAM_G_SIZE);

  /* Perform the IOCTL to write data to graphics memory */

  ramg.offset = offset;
  ramg.nbytes = nbytes;
  ramg.value  = (FAR void *)data;  /* Need to discard const qualifier */

  ret = ioctl(fd, FT80X_IOC_PUTRAMG, (unsigned long)((uintptr_t)&ramg));
  if (ret < 0)
    {
      int errcode = errno;
      ft80x_err("ERROR:  ioctl(FT80X_IOC_PUTRAMG) failed: %d\n", errcode);
      return -errcode;
    }

  return OK;
}